Material handling assembly



Jan. 16, 1968 M. NELSON MATERIAL HANDLING ASSEMBLY 2 Sheets-Sheet 1 Filed Oct. 21, 1965 INVENTOR mRw/v Naso/v' ,4

ATTURNEYS \Eii M- NELSON MATERIAL HANDLING ASSEMBLY Jan. 1a, 19 8 2 SheetsSheet 2 Filed Oct. 21, 1965 INVENTOR MARVIN NELSON QQN K Q E wm Q E 3 Q United States Patent 3,363,929 MATERIAL HANDLING ASSEMBLY Marvin Nelson, 153-40 77th Road, Flushing, N.Y. 11367 Filed Oct. 21, 1965, Ser. No. 499,585 Claims. (Cl. 29488) ABSTRACT OF THE DISCLOSURE An attachment for a fork lift truck for grasping and lifting hard-to-reach bulky objects, for carrying the objects and for releasing them at locations and elevations limited only by the vertical lift capacity of the supporting machine. A leg is connected to a vertically movable member of the truck and a stem is pivotally joined to said leg. A first pair of arcuate arms are pivotally attached to the forward end of the stem, with hydraulic means for pivoting said arms. A second pair of arms is pivotally connected to the first pair of arms. The distance between the front ends of the second pair of arms is sufficient to pass a body round in cross section therethrough, the rear ends of the second pair of arms being in the path of movement of the round body when passing through whereby the arms are tilted into clamping engagement with the round body.

This invention relates to a material handling assembly and more particularly concerns a device or attachment which can be mounted on a fork lift truck, or other machine with vertical lift capabilities, for grasping and lifting hard-to-reach bulky objects, for carrying the objects and for releasing them at locations and elevations limited only by the vertical lift capacity of the supporting machine.

A principal object of the invention is provision of a device of the character described which is self-adjusting to seek out and grasp hard-to-reach objects.

According to the invention, there is provided a material handling assembly including a pair of pivotally mounted hydraulically driven arcuate rear arms and a pair of arcuate, spring loaded forward arms pivotally attached to the rear arms. Upon forward movement of vertical lift machine equipped with the device to grasp an object, the forward arms are cammed closed around the object by the object itself. The rear arms are closed by action of pistons in a master hydraulic cylinder forming part of the device. The device has an articulated or jointed stem with spring loaded parts so that the arms can be swung laterally. from acentral position when required and forcefully deflected. The arms will return to the central position when released from the lateral deflecting forces. This turning or swinging capability of the arms helps the device to adjust itself to seek out and grasp hard to reach objects. The device can be easily mounted on and removed from a fork lift truck or other mechanical lift machine so that the me chanical lift machine can be put to other uses without the device, so that the device can be interchanged with other devices of like type but different sizes and load handling capabilities, and so that the device can be moved at will to other fork lift trucks or lifting machines. The device may have its own separate hydraulic drive system or may have a hydraulic system which can take off hydraulic power from the mechanical lift machine or truck if available. The hydraulic system is provided with controls under the control of an operator for adjusting pressure applied by the arms to the object or load being held and carried by the device. The arms can be provided with different shaped forms to handle objects of different shapes. The arms can be provided with friction linings to increase their gripping ability. The hydraulic system can be arranged to operate the rear arms automatically when the arms encircle the load.

For further comprehension of the invention, and of the objects and advantages thereof, reference will be had to the following description and accompanying drawings and to the appended claims in which the various novel features of the invention are more particularly set forth.

In the accompanying drawings forming a material part of this disclosure:

FIG. 1 is a top plan view of a device embodying the invention, parts being shown broken away.

FIG. 2 is a longitudinal sectional view taken on line 2-2 of FIG. 1.

FIG. 3 is an enlarged fragmentary sectional view taken on line 3-3 of FIG. 1, and

FIG. 4 is a plan view similar to a part of FIG. 1, with parts of a dual line hydraulic system shown diagrammatically and other parts in section.

Referring first to FIGS. 1, 2 and 3, there is shown an assembly 10 including a central leg 12. This leg is a flat member with a pair of rearwardly extending flat parallel flanges 14. These flanges receive between them a post 16 extending forwardly from a plate 18 forming part of a vertically movable carriage to fork lift truck on other vertical lift machine. The flanges have aligned holes to receive bolts 20 secured by nuts 21 and carrying spacer washers 22. The leg 12 is thus securely but removably attached to the post 16 and extends rigidly forward in a horizontal plane from vertical plate 18.

At its forward end, leg 1 2 is disposed between the rear- Wardly located flat parallel horizontal flanges 24 formed at the rear end of a massive flat stem 26. Stem 26- is pivotally connected to leg 12 by a pivot pin 28. The pin 28 is axially vertical so that stem 26 can swing or rotate in a horizontal plane with respect to leg 12. Angular brackets 32 and 34 are provided at opposite sides of the leg 12 and stem 26. These brackets have facing spaced flanges in which are threadedly engaged eyebolts 35, 36. Coil springs 37 are secured at opposite ends to the eye bolts. The springs are adjustably tensioned by turning the eyebolts and serve to keep stem. 26 axially aligned with leg 12. The springs permit lateral angular rotation and deflection of the stem if the stem is forcefully deflected. When the stem is released the springs return the stem to axial alignment with leg 12.. In order to limit the range of angular turning movement of the stem, there is provided a pair of adjustment screws 38 engaged in flanges 40 carried by brackets 32. The forward ends of the screws 38 are adjustably spaced from flanges 42 carried by brackets 34. The screws can be advanced to contact flanges 4 2 whereupon the stem will be locked against rotation with respect to the leg.

In stem 26 near its fOl'WBId end is a recess 44 in which is slidably seated a single acting fluid cylinder device 45. This cylinder is axially horizontal and extends axially transversely of the axis of stem 26. The cylinder is loose fitted in and re-movably held in the stem 26 by a clamping plate 46 and bolts 48. 'In the cylinder is a piston 50*which has a piston rod 52 extending axially out of the cylinder. A flexible conduit 54 is connected to the side of the cylinder to supply fluid under pressure to extend the device 45.

Conduit 54 terminates at one end of a conventional manually or pedally-operated hydraulic pump and cylinder assembly 60. Assembly 60 will be located at the working position of an operator of the lifting machine on which the device Ill is installed.

The assembly -60 has a lever 61 which can be hand or foot operated to pump fluid under pressure through the conduit or line 54 to cylinder 45. The assembly .60 has two control valves 62 and 64. Valve 62 is a two position reversible check valve which in one position permits fluid to pass out of the assembly cylinder 45 while preventing flow in the opposite direction, and in the other position the valve 62 permits fluid to pass only fro-m cylinder 45 to assembly 60. Valve 64 is an adjustable or spring throttle type of valve which regulates the size of orifice opening through Which fluid passes to line 54. This valve regulates the pressure applied to the fluid and thus controls the pres sure applied to piston 50in cylinder device 45.

The cylinder device 45 has hooked outer ends 66 pivotally engaged in slots 65 formed in two lever arms 68. These arms are rigidly secured to rear outer sides of two arcuate arms as. Springs 69 connect arms 60 with sides of stem 26. Rear ends of arms 66 are pivotally secured by pivot bearings 70 to laterally extending flanges 72 formed on the forward end of stem at. The forward end of the stem has a cylindrically curved forward edge 74. This edge is continuous cylindrically with friction linings 75 secured to inner concave sides of arms 6'6. The linings are secured by screws 7 6 to the arms; see FIG. 2.

In the forward ends of arms 66 are recesses 77 open at inner sides of the arms as. Opposite top and bottom walls of the recesses are defined by flanges 7'8, 79. Between these flanges are pivotally mounted two arcuate forward arms 80. The arms 80 are engaged by pivot bolts 82. Inside the recesses extend coil springs 84 which are seated in housings 85 extending outwardly of arms 66. The inner ends of the springs 84 bear on outer sides of the arms 80 at rear ends thereof. These springs bias the arms 80 so that their rear ends 80 normally project laterally in- I wardly of the semicylinder defined by the arms 66. The arms 80 can be pivoted so that forward ends 80 of the arms 80 approach each other and the inner ends 80' will be retracted outwardly into recesses 77 while compressing springs 84. In so doing, the arms 80 will assume the dotted line positions shown in FIG. 1. Friction linings 86 can be secured to the concave inner sides of arms 80 by screws 88. The arms together with arms 66 and edge 74- of the stem 25 define a cylindrical surface extending arcuately about 270. The arms 66 with edge 74 define a cylindrical surface slightly less than 180. Thus a cylindrical body B such as a drum can freely enter between the widely spaced ends 80" of the arms 80.

In operation of the device, the lift truck will advance to a position where a cylindrical body such as body B is to be grasped. As the truck advances device 10 forwardly the arms 66 pass body 13 until the rear ends 80 of the arms contact body B whereupon body B will cam the arms to turn on pivots 02. The curved inner sides of arms 80 will then assume a position cylindrically continuous with the inner sides of arms es. The rear half of body B will be engaged between arms 66. Then the operator of the device can operate the valves 62 and 64 to apply fluid under pressure to cylinder 45 and piston 50. Rear ends of arms 80 are engaged at rear walls 89 of recesses 77 and springs 84 are compressed. By adjusting valve 64 the pressure on the body B can be regulated. Springs 69 will then be extended in tension.

It will be noted that when the device 10 is advanced to engage body B, stern as may be deflected laterally if the body B is displaced laterally from the axis of the stem 26 and leg 12. However, when the lift truck is raised and withdraws the device with body B engaged between the arms 66, 80 the stem 26 will automatically align itself with leg 12 under the control of springs.

When body B is to be unloaded from the device, the position of valve 62 can be reversed to receive hydraulic pressure. Springs 69 will retract and draw arms 66 apart. Then while body B is held stationary by its own weight or some other force the device 10 can be withdrawn from the body, whereupon arms 80 will pivot to the open position shown in solid lines in FIG. 1.

FIG. 4 shows another construction in which device 10a is similar to device 10, and corresponding parts are identically numbered. In device 10a the hydraulic system is arranged so that the arms 66 are operated automatically When the arms encircle a load 13'. A valve 90 having an operating pushbutton 91 is installed into the forward side 74 of stem 26. The pushbutton projects forwardly between arms 65. A valve has a movable piston 92 biased forwardly by a coil spring 93 The piston has a passage 94 which is normally out of alignment with inlet 95 and outlet of the valve. When the piston is retracted by contact of load B with pushbutton 91 the inlet and outlet are aligned through passage 94 in the piston.

Fluid input line or conduit 54a is connected to inlet 95. Outlet 96 is connected via a short pipe 97 to inlet 98 of cylinder 45a. A fluid return line 99 is connected to outlet fitting 100 of cylinder 45a. Conduit 54a is connected to a valve 62a. This valve has a manually rotatable core 101 with a 90 passage 104. The fluid return line 99 is connected to valve 62a at a position spaced 90 from fluid return line 99a. Fluid inlet line 54b is connected to valve 62a at a point 180 from line 99 and 90 from the point of connection of line 54a. Lines 5412 and 99a are connected via conventional quick release fluid couplings 106, 107 to outlet and inlet ends 108, 109, respectively of a hydraulic pump 110. This pump may be the local hydraulic pump of the fork lift truck or the lifting machine. Valve 62a is located at the operators position P of the lifting machine. An adjustable spring-loaded or throttle type valve 64a is connected in line 54a. to regulate fluid pressure applied to cylinder 45a.

Device 10a operates in substantially the same manner as already described for the device 10, except that the device makes use of a dual line hydraulic system; pump 110 may be the same one as that which operates the fork lift mechanism, and the rear arms 66 operate automatically when load B contacts pushbutton 91. When the pushbutton is retracted, communication is established between fluid inlet line 54a and the inlet 98 of cylinder 45:; as piston 92 is retracted. The core 101 of valve 62a will be rotated from the position shown in FIG. 4 to establish direct contact between the pump outlet 108 and line 54a. Normally open valve 64a will be adjusted to regulate the pressure in the line 5411.

If objects other than cylindrical ones are to be handled it is possible to remove certain ones of the screws 76, 88 from arms 66 and S0. The screws and screwholes can then be used to attach appropriately shaped forms to the arms. These forms will accommodate the device to irregularly or specially shaped objects or to loads of smaller diameters than loads B and B.

The device 10 and 10:; can be made up in various sizes to accommodate loads of different sizes and weights.

While I have illustrated and described the preferred embodiments of my invention, it is to be understood that I do not limit myself to the precise constructions herein disclosed and that various changes and modifications may be made within the scope of the invention as defined in the appended claims.

What is claimed is:

1. An attachment for a fork lift truck or the like having a vertically movable member, comprising a leg attachable to said member so that the leg extends forwardly outwardly of said member and is movable therewith, a stem pivotally joined to said leg and extending forwardly of the leg, spring means operatively connecting said stem and leg so that said stem is normally held in axial, horizontal alignment with said leg by said spring means, a first pair of arcuate arms pivotally connected to the forward end of said stern and arranged in a generally semicylindrical configuration, hydraulically operated means connected to the arms for pivoting the same inwardly toward each other to grip a body therebetween, a second pair of arcuate arms pivotally connected to and carried by said first arms, other spring means biasing the second arms rotationally so that rear ends thereof are displaced laterally inward of the second arms toward each other while forward ends of the first arms are displaced laterally outward and are spaced apart a distance greater than the spacing of forward ends of the first arms, whereby forward ends of the second arms will freely pass said body when the attachment is advanced by the truck, and whereby said body will contact rear ends of the second arms and will cam them to an enclosing position around the body when the attachment is advanced until said body contacts the first arms.

2. An attachment according to claim 1, wherein said arms have friction linings secured thereto to increase frictional gripping of said body by said arms.

3. An attachment according to claim 1, further comprising adjustable spacer means extending between said leg and stem at opposite sides thereof to limit angular turning of the stem with respect to the leg to a set angular range.

4. An attachment according to claim 1 further comprising quick detachable fastening means attaching the leg to said member so that the attachment can be quickly removed from and replaced on said member.

5. An attachment according to claim 1, wherein said hydraulic means comprises a cylinder, piston means in said cylinder, piston rod means connected to the piston means respectively and extending outwardly of opposite ends of the cylinder, levers connected between the first arms and said piston rod means for pivoting the first arms inwardly toward each other, further spring means for pivoting the first arms outwardly when hydraulic pressure is released, and means for applying hydraulic pressure to said piston means in the cylinder.

6. An attachment according to claim 1, wherein said hydraulic means comprises a cylinder, piston means in said cylinder, piston rod means connected to the piston means respectively and extending outwardly of opposite ends of the cylinder, levers connected between the first arms and said piston rod means for pivoting the first arms inwardly toward each other, further spring means for pivoting the first arms outwardly when hydraulic pressure is released, a single conduit connected to said cylinder for applying fluid pressure thereto, and a valve controlled hydraulic pump connected to the cylinder via said conduit for applying fluid pressure in said cylinder.

7. An attachment according to claim 1, wherein said hydraulic means comprises a cylinder, piston means in said cylinder, piston rod means connected to the pistons respectively and extending outwardly of opposite ends of the cylinder, levers connected between the first arms and said piston rod means for pivoting the first arms inwardly toward each other, further spring means for pivoting the first arms outwardly when hydraulic pressure is released, a first conduit connected to said cylinder for passing fluid into said cylinder, a second conduit connected to said cylinder for passing fluid out of the cylinder, and a source of fluid under pressure connected to said conduits for feeding fluid to the first conduit and receiving fluid from the second conduit.

8. An attachment according to claim 1, wherein said hydraulic means comprises a cylinder, piston means in said cylinder, piston rod means connected to the piston means respectively and extending outwardly of opposite ends of the cylinder, levers connected between the first arms and said piston rod means for pivoting the first arms inwardly toward each other, further spring means for pivoting the first arms outwardly when hydraulic pressure is released, a valve carried by said stem, said valve having an operating element extending forwardly between said first arms for contact by said body, a first conduit connected to said valve for passing fluid into said cylinder via said valve when said element is retracted by contact with said body, a second conduit connected to said cylinder for passing fluid out of the cylinder, a source of fluid under pressure connected to the conduits respectively for feeding fluid to the first conduit and for receiving fluid from the cylinder via the second conduit.

9. An attachment according to claim 8 further comprising another valve connected between the conduits and said source of fluid for selectively passing fluid from said source to said cylinder and for passing fluid back from said cylinder to said fluid source.

10. An attachment according to claim 9, further comprising a further valve connected to the first conduit for controlling pressure of fluid applied to said cylinder, and quick release couplings removably connecting said conduits to said source of fluid under pressure.

References Cited UNITED STATES PATENTS 2,645,372 7/1953 Broersma 214-652 2,683,546 7/1954 Sherriff 29488 X 3,227,299 1/1966 Draxler 214-O X HUGO O. SCHULZ, Primary Examiner. 

